6837 FM comms

[brandon]

For the past couple days I have been hearing occasional FM voice activity from US military stations 6837. It's pretty scratchy here into SoCal but I suspect its coming from somewhere in the western US. I'm willing to bet this freq will be active again tomorrow, so it may be worth watching.

Here is a recording of some traffic: 6837.mp3

Similar traffic noted last year on 7838 and a 3 MHz freq. (sorry I forgot the exact)

 

[Token]

For the past couple days I have been hearing occasional FM voice activity from US military stations 6837. It's pretty scratchy here into SoCal but I suspect its coming from somewhere in the western US. I'm willing to bet this freq will be active again tomorrow, so it may be worth watching.

Here is a recording of some traffic: 6837.mp3

Similar traffic noted last year on 7838 and a 3 MHz freq. (sorry I forgot the exact)

And the 7838 kHz traffic was in June of last year, so possibly a regular or scheduled event / exercise. The signal is fair to strong here, but I have only seen it key up a few times, and have heard no traffic that might identify source. Based on the few transmissions I have seen so far there may be a PL on the TX.

T!

 

[krokus]

Why do you think that is military comms?

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[Token]

Why do you think that is military comms?

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The use of this frequency range with NFM in the US south west has been tied to military communications (often by message content, sometimes by RFDF to specific facilities, most often Fort Irwin or 29 Palms what I hear at my location) in the past.

Time of day combined with signal strength and frequency suggested south western US. The mode is NFM.

Callsigns, content, and speech patterns heard on 6837 kHz suggest similar traffic to what has been observed in past military communications. If you listen to the audio clip Brandon provided you will hear them providing a count of M16's and M9's in the report. Since they mention a count of 142 M-16's, one would think it is quite possibly a military unit.

In the past they have included counts of simulated KIA/WIA/MIA during events.

T!

 

[krokus]

The lack of phonetics and terminology makes me think someone else is using the freqs.

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[SCPD]

What time do you have it logged at?

 

[kc4jgc]

Based on the few transmissions I have seen so far there may be a PL on the TX.

Listening to the mp3 file, there is DEFINITELY CTCSS being used. I'd have to do a comparison; I'm thinking 141.3 hz.

I'm amazed that FM is being used on HF that low....

 

[Token]

Listening to the mp3 file, there is DEFINITELY CTCSS being used. I'd have to do a comparison; I'm thinking 141.3 hz.

I'm amazed that FM is being used on HF that low....

In the recording the tone is 151.4 Hz, however I am not sure that is the same thing that has been used for all transmissions.

T!

 

[sheilaaliens]

For the past couple days I have been hearing occasional FM voice activity from US military stations 6837. It's pretty scratchy here into SoCal but I suspect its coming from somewhere in the western US. I'm willing to bet this freq will be active again tomorrow, so it may be worth watching.

Here is a recording of some traffic: 6837.mp3

Thank you for that audio sample. If possible, please share more recordings of any military stuff you hear over the next couple of months, as many of us are following the Jade Helm exercises closely and dont have the equipment or knowledge to tune in ourselves. Thank you!!!

 

[SCPD]

Listening to the mp3 file, there is DEFINITELY CTCSS being used. I'd have to do a comparison; I'm thinking 141.3 hz.

Per Sorcerer's decode it's 146.2 for about 95% of the time -- but it does register 151.4 a few times.

 

[brandon]

I also get 5Z (151.4 Hz) when running it through the decoder on the high quality Wav file. Suspecting it's probably standard NATO 150.0 Hz tone, not sure my decoder even supports.

 

[brandon]

What time do you have it logged at?

The traffic was mostly in the afternoon (west coast USA). Between 2200 to 0200 UTC.

 

[Token]

I also get 5Z (151.4 Hz) when running it through the decoder on the high quality Wav file. Suspecting it's probably standard NATO 150.0 Hz tone, not sure my decoder even supports.

Dead on Brandon, 150 Hz it is. Looking at it without using a PL / CTCSS classifier (my last post was based on WinRadio Digital Audio Suite Audio Signal Decoder calling it 151.4 Hz) that tries to fit it in a niche and you will see it is 150 Hz for the entire recording.

T!